The treatment of fibers, fabrics and laundry with conditioning agents, such as fabric softeners, anti-wrinkling agents, antistatic compounds and other preparations designed to improve the properties of the treated material is a well-known operation. It is practiced most by the housewife who adds fabric softening solution in the final rinse cycle of an automatic washing machine. The substantive cationic softening agent usually employed strongly adheres to the laundered textiles and remains thereon during subsequent spin drying and heat drying. Of course, such processes require that the conditioning agents employed be highly substantive or else they will be removed with the rinse water, yielding insufficient softening activities.
In efforts to find other ways of depositing softening agents on the surfaces of fibers and fabrics, pressurized sprays have been applied to the articles to be treated either before or after drying. Even when the sprays are of very fine droplets of a solution of conditioning agent it is a tedious task to apply the spray evenly to all the articles being treated. When the spraying apparatus is included as an integral part of a drying apparatus, such as an automatic laundry dryer, the costs of the spraying apparatus, control means for it and installations of these are often so great as to make such a treatment uneconomical. Instead of using a spray, solid conditioning agents, absorbed onto or impregnated into flexible papers, cloths or sponges have been employed in the dryer. U.S. Pat. No. 3,442,692 teaches that substantive cationic conditioning compounds vaporize into the moist atmosphere of the dryer and are sorbed by the materials being tumbled therein. Although it is considered that many useful cationic conditioning agents are of such high boiling points that they are incapable of vaporizing under ordinary drying conditions, U.S. Pat. No. 3,442,692 is cited as an example of another way to use conditioning agents in the automatic laundry dryer.
Although the disadvantages of conventional softening methods, utilizing the washing machine, and more recently developed treating operations, using the automatic laundry dryer, are known, before the present invention there was no acceptable simple and economical way to apply liquid conditioning agent to fabrics to be softened or to be made antistatic in the automatic laundry dryer. Now, by following the method of this invention, good conditioning may be obtained economically and conveniently and without the necessity for the installation of complex equipment.